Brake.



J. ZULLER & R. SGHUSTER.

BRAKE.

APPLICATION FILED JUNE 4, 1914.

Patented Mar. 16, 1915.

3 SHEETS-SHEET 1.

J. ZOLLER & R. SCHUSTER.

BRAKE.

APPLICATION FILED JUNE 4, 1914.

1,131,810. i Patent-,ed 11111.16, 1915.

3 SHEETS-SHEET 2.

J. ZLLBR 6a B.. SCHUSTER.

BRAKE.

APPLICATION FILED JUNE 4, 1914.

Patented Mar. 16, 1915.

3SHEETS*SHEET 3.

' the braking members with l which, as is known,

STATES PATENT ernten.

'Jonann zonnen Nn Bossier scnusrnnp or manna, .anemia-numana.

' snags. i

manera.

To all fwiom it may concern.'

Be it known that we, JOHANN ZOLLER and ROBERT SCHUs'mR residing at Schlagergasse 10, Vienna, IX, ustria-Hungary, have 1nvented certain new and useful Improvements in and Relating to Brakes, of which the following is a specification.

This invention relates to brakes of' the type adapted to effect the required retardi'ng effort on the crank shaft of a primary mover or on a s haft formng part of a system of transmission but more particularly to the type known as dynamometers.

Our invention consists in the improved constructions hereinafter fully described.

It is known that all brakes serving for braking mechanical work Suder from the serious defect that theyy do not permit of steady and smooth braking. The main reason for this is what is called the locking of the brake drum, not only gives rise to shocks, but also produces highly unfavorable strains on the brake. This locking of the brake members is particularly disadvantageous in the mechanical brakes employed as dynamometers as in these brakes, bv the locking` of the brake members with the brake drum the resistance of the brake, which is so important for exact measuring, is lost. Now it has been found that all the said defects inherent in 'mechanical brakes' can be eliminated by immersing the brake element .through the interior of which liquid cooling agents circulate, with the braking members arranged upon it in a vessel filled with lubricants, so that the braking is effectedA with permanently equal external lu' brication and constant uniform internal cooling.

A brake construction particularly suitable for dynamometers, is illustrated in the accompanying drawing by way of example.

Figure l is a longitudinal section of the brake. Fig. 2 is a section on the line II-II in Fig. 3. Fig. 3 is a section on the line vITT-Hl in Fig. 1. Fig. 4 is a horizontal section on the line lV-IV in Fig. 3. Figs.

5 and 6 represent details .of the brake in sec.

tion and in elevation on an enlarged scale. Figs. 7 and 8 represent a particularly advantageous construction of the brakev drum in longitudinal 'section and-in cross-section respectively. Fig. 9 illustrates the perliph ery of a brake drum in development. ig'. 10 represents the .developed 4 periphery of `brake drum 2 and drawing,

'bined with a holder 10 and discharge of the cooling agent. l

The brake consists of a shaft 1 coupled in the known manner with the engine, the

vbrake drum 2 being mounted on this shaft.

A series of brake blocks 3 rest on the The brake drum 2 with the brake blocks 3 arranged thereon is inclosed in a speci-ally formed casing 4 which presents the form of a. closed dish fitting as closely as possible around the body of the brake drum. This casing 4 serves for the reception of liquid lubricants such as oil or oil emulsions and the like and is of such'a size that the brake drum with theblocks arranged around it can be wholly or almost wholly immersed in the lubricant. On its side walls the casing 4 presents two bearings 5, 5 comprising bores in which the brake shaft 1 is rotatably mounted. A good joint is obtained between the brake shaft and the lubricant receptacle by means of stuiiing boxes 6, 6. The lubricant receptacle ,4 is supported by means of its journals 5, 5 which have bearings in a block 'Z provided with ball bearings 8, 8.

In the construction illustrated in .the the braking members f the brake consist of simple blocks distributed over the entire periphery of the brake drum and arranged parallel with its generatrix. Lignum Sanctum has proved to be a particularly suitable lmaterial for the brake blocks. In place of the wide brake blocks represented 1n Fig. 1, a plurality of brake blocks composed of smaller blocks can be employed as shown in Fig. 5.

Each'of the braking members 3 is comcomprising on each 0f its ends arib 11, 11i On each side of the brake drum a guide plate 12, 12 arranged on the (walls of the lubricant receptacle 4 is xed; onits periphery this plate is provided with a series of radially directed guide slots 13 (Fig. .6) the ribs 11, 11 of the brake block holder 10 being inserted in these slots.

Fach of the 'brake block holders 1'() is provided at the middle with a web 15 on which the pressure mechanism pressing the brake block holders or the brake blocks against are pressed with` equal4 Specification of Letters Patent.' I Patented liliana". 16, 11915. y' Application Bled J'une4, 1914. Serial No. 842,880. i

i the brake drum acts.V In the embodiment y 22 andaround the rbrake blocks resting on of the invention illustrated in the drawing, this pressure mechanism consists of a cable or band 1S loosely surrounding the brake block holders, so that whenthe band is tightened, it simultaneously and uniformly applies all the brake blocks 3 to the brake drum. With this object" tensioning mechanism is provided on the lubricant receptacle 4 for tightening the ends of the band; in the embodiment of the invention here illustrated, this mechanism consists of a screw spindle 2O rotatably mounted and adapted to be operated by the hand wheel 19 and a longitudinally displaceable nut 21 secured against rotation. The nut 21 is formed as a cross head and provided with two bolts 22, 23 upon which the ends of the band18 are fixed in the manner shown in Fi 2. The band passes downward from the xing bolt brake blocks arranged upon the brake drum; it then'passesover a compensating roller 24 tixed to the bottom of the lubricant receptacle. The length of cable or band running off this roller 24 is again passed around the brake block holders upon the brake drum,- its end being secured tothe. bolt 23 of the cross head 21. The cable is thus divided into two.- groups of cable turnsby the roller 24 and when traction is exerted on the end secured to the cross head, these groups insure the simultaneous and uniform application of all the i the brake drum. The method of guiding the cable, the construction and arrangement of the tensioning mechanism and the number and arrangement of the compensating rollers can be modiied in any convenient manner Without departing from the principle of the invention.

In order that when slackening the cable, that is to say releasin the brake, the brake blocks may be lifted immediately from the brake drum, the brake block holders are caused to bear by springs 26 against the annular plates 12.(see Figs. 5 and l).

By means of the arrangements described an extremely sensitive adjustment of the application of the brake blocks is insured without impeding the access' of the lubricant contained in thelreceptacle 4 to the places at which the brake blocks are applied.

In order to permit of combining the drum cooling, which is known per se, ,in the most effective manner with the lubricant bath for the brake drum describedabove, it is necessary to adopt a special method of causing the cooling agentto circulate in the system, as otherwise the favorable action of the bath lubrication would be yentirely lost. With this object the arrangement is adopted that at" adjacent places on the brake drum the `existence of 'large differences of temperature.

iai-fthe'.eirculaang'oling agent is avoided-Y The most simple method of insuring this is by forming the peripheral cooling jacket and the conduits for the lsupply and dis- .charge of the cooling medium in the following` manner:

he brake drum 2 (Figs. 7 and 8) 1s provided on yits periphery in a manner known per-se with ribs 29 which as shown by the developed cooling jacket in Fig. 10 are relatively staggered in a. special manner. By this means the cooling jacket of the brake drum is divided into a Series of chambers K,K, which produce a zigzag circulation of the cooling agent in the brake drum jacket. As shown in'Figs. 10 and 7 the ribs 29 built into the chambers K1 and K5 are connected one with the other by ribs 30 for a reason hereinafter explained, so that the chamber li'.1 is separated from the chamber K6 and the chamber K5 from the chamber K10.

The fresh cooling water is conducted into l .chamber K6 the coolingagent flows throlgh 10 the chambers K7` to Ko into the chamber and leaves the jacket of'the drum through the discharge aperture 35 (Figs. 7 and 10).

The cooling agent cir-` The discharge aperture 35 communicates t with a bore 36 provided in the 'brake drum and this opens in the axial bore in the brake shaft 39.

A discharge socket 40 is provided at the end of the hollow brake'shaft (Fig. 1) and through this the heated-'cooling water flows outof the brake mission aperture 31V (Fig. 9) into the cooling jacket of the brake drum and allowed to circulate in an uninterrupted cycle (see the direction indicated by the arrow in Fig. 9) through the jacket ofthe drum, the chamber K1 would always be filled with fresh and therefore cold water and the adjacent chamber K#x with the hottest cooling water. This great difference. of'te'mperature between the two adjacent chambers would not only give rise to unfavorable local modifications of the viscosity of the lubricant adhering to the periphery of the drum, butwomd 'also give rise to unfavorable tensions in the ribsdividing the chambers. This great difference of temperature between bers is avoided in the form of brake drum illustrated -in Fig. owing to thevl provision of the circulation the two adjacent chaml 10 of the ydrawing as drum.'- If the fresh cooling water were simplyadmitted through the ad passage 34"cooling water of mean heating temperature mannaro is re-conducted into the chamber K, whereby the difference ottemperature between the cooling agentin the chambers K1 and K8 is reduced. lin addition to this, the arrangement described ai'ords the further advantage that the ribs 29, 30 of the cooling jacket can be made very thirf and caused to run almost to a point toward the periphery of the drum. lin this construction the periphery 41 of the brake drum can be formed of very thin material such for example as sheet steel by which division of the brake drum the formation of the brake drum casting is very largely facilitated.

in order to avoid the heating of the tres cooling water iowing through the admission pipe 33 into the brake drum by the heated cooling water ire-conducted over the admission pipe 33, this pipe can be formed as a double pipe, the interval being lled with substances which are bad conductors of heat such :tor example as ashes or asbestos.

lt will of course be understood that the arrangement described above can be adopted for all brakes usually employed for technical purposes, as owing to their construction, theyV can readily be tted to any rotary brake member. rlhe cable or strap arrangement described can either be employed for applying brake blocks slung directly around the brake drum, in which case the brake acts merely as a cable brake. y

The brake is especially advantageous when employed as a dynamometeras owing to the combined internal cooling and external lubrication of the brake, it presents extraordinarily great resistance within very wide limits of output, so that very exact measuring is eected. When employed as a dynamometer the manipulation of the brake is as follows: lin the first place the lubricant reservoir i is filled with oil or some other suitable liquid lubricant to such an extent that the brake mechanisms contained in the receptacle are covered entirely or almost entirely bythe bath of lubricant. en this has been edected, the internal cooling of the brake drum is started .and the engine to be tested is coupled in the known manner with the brake drum. rll`hen by rotating the hand wheel 19 the ends of the cable 18 passed around the brake blocks 3 are applied until resistance arises in Vthe system. During the entire braking operation, the lubricating liquid flows from all sides uniformly between the .brake blocks and brake plate, so that a thoroughly uniform lubrication of the internally cooled brake drum is permanently insured. When iuctuations in the load ot the engine to vbe braked occur, it is only necessary to etiect very small adjustments by means of the hand wheel 19 whereby the brake is immediately re-set in 'its condition .of resistance. @n braking the turning `moor they cable can beI ment of the brake plate 2 is transmitted to for example as a spring balance, weights, l

or gages on its lever arm' li (see Fig. 3). rihe power of the engine can be calculated in the known manner from the turning moment and the number of revolutions read upon the revolution counter 44. ln the present case the power agrees exactly with the useful work of the engine, as owing -to the special formation of the brake mechanism, all errors of measurement which would otherwise exist, are allowed for and the great permanency of the brakewithin extraordinarily wide power limits permits of taking extremely exact readings.

Having thus described our invention and explained the mode of operation thereof, we claim and desire to secure by Letters Patent o l. lin a mechanical brake, the combination of a frictional braking member, means for applying a cooling medium interiorly thereo1f`,and means for applying a lubricant errteriorly ofi said braking member.

2. ina mechanical brake, the combination of a frictional braking member, means tor applying a cooling medium interiorly thereof, and a casing adapted to contain lubricant and in which said braking member is arranged.

3. ln a mechanical brake, the combination of a brake drum withmeans for circulating a .liquid cooling medium in the interior thereof, braking members adapted to co-act with said drum, and a casing adapted to contain lubricant and in which said drum and braking members are arranged.

4f. lin a mechanical brake, the combination of a brake drum with means for applying a cooling medium interiorly thereof, braking members adapted to co-act with said drum, guides for said braking members` and a casing adapted to contain' lubricant and in which said drum and braking members are arranged.

5. ln a mechanical brake, the combination of a brake drum with means *for applying a coolingmedium interiorly thereof., braking members adapted to co-act with said drum, a casing adapted to contain lubricant and in which said drum and braking members are arranged, and guides for the braking members carried by said casing.

6. lin a mechanical brake, the combination of a brake drum with means for applying a cooling medium interiorly thereof, braking members adapted to co-act with said drum, plates provided with slots for guiding said braking members, and a casing adapted to contain lubricant and in which said drum and braking members are arranged.

lil@

7. lln a mechanical brake, the combination and adapted to force the same into engagement with said drum, and a casing adapted to contain lubricant and in which said drum and braking members are arranged.

9. In a mechanical brake, the combination -of a brake drum with means for applying a cooling medium interiorly thereof, braking members adapted to co-act with said drum, cables passing about said braking members and adapted to force the same into engagementwith said drum, rollers over which said cables are guided, and a casing adapted to contain lubricant and in whichsaid drum and braking members are arranged.

l0. In a mechanical brake, the combination of a brake drum with means for circulating a liquid cooling medium in the interior thereof, braking members adapted t0 co-act with said drum, a casing adapted to contain lubricant and in which said drum and braking members are arranged, and means whereby said cooling medium is'fed to and discharged from said drum through said casing.

l1. In a mechanical brake, the combination of a brake drum having a plurality of peripheral cooling chambers and an inlet and outlet for the cooling medium, braking members adapted to co-act with said drum, means connecting a cooling chamber adjacent said inlet to another cooling chamber between said inlet and said outlet, and a casing adapted to contain lubricant and in which said drum and braking members are arranged.

12. In a mechanical brake, the combination of a brake drum with means for applying a cooling medium interiorly thereof, braking members adapted to co-act with said drum, a casing adapted to contain lubricant and in which said drum and braking members are arranged, and a support for said casing in which the latter may be rocked. v In testimony whereof we affix signatures in presence of two witnesses.

JOHANN ZOLLER. ROBERT SCHUSTER. Vitnesses: Y

AUGUST FUGGER, ADA MARIA BERGER. 

